Unique JavaScript embeds cine stacks in teaching files

Attempts to relieve restrictions on teaching file systems that can use only static images have generally failed to achieve simplicity. A new paper introduces a simple method for embedding user-controlled cines into teaching file web pages using JavaScript.

"Conventional teaching files, and even dynamic interactive HTML schemes, are restricted to static views of a single radiograph, or single CT or MR slice, even though diagnosis of many processes requires multiple images," said Dr. Daniel Cornfeld, an assistant professor of radiology at Yale University School of Medicine.

Cornfeld's technique creates web-based scrollable cine from a stack of images. The system is portable and can be used to show cases at conferences, make web-based teaching files, or test residents (AJR 2008;(39):190).

"With this method, you can quickly and easily incorporate entire stacks of CT or MR images into online teaching files," Cornfeld said.

It is also easy to create PowerPoint hyperlinks to web pages containing image stacks, so users never have to leave PowerPoint during talks to display image stacks, he said.

The advantage of JavaScript over Java is that JavaScript does not require knowledge of Java to use or install, as it is a completely different computer language from Java. It does not require compilation or installation of JRE (Java Runtime Environment) on user computers, Cornfeld said.

"JavaScript is a simple text file interpreted by any Internet browser," he said. "No programming skills are necessary to make cases. The JavaScript is something the user never has to touch - it's just a file that sits in the folder."

Another JavaScript advantage is that no applets or cookies are placed on user computers, meaning users can access scrollable cine images from any computer with an Internet browser without the need to save, download, or install third-party applications, such as an image viewer, compiler, or runtime environment.

"This makes the process completely portable," Cornfeld said. "I routinely use this technique to transport cases and to show cases at departmental and multidisciplinary conferences."

The Cornfeld technique can also be used to view cases remotely via the Internet.

Limitations exist, according to Cornfeld. First, since the script is not meant to replicate a complete DICOM viewer, the user is unable to perform window and level changes. Also, the security settings on some computers block execution of JavaScript files. This can be remedied by changing the settings to allow ActiveX content to run.

Cornfeld said the code is available free by contacting him at daniel.cornfeld@yale.edu.